Engineered structural board

ABSTRACT

An engineered 2″×8″ equivalent board is formed from a standard wood 2″×4″ board. The 2″×4″ board is bifurcated longitudinally to form opposed rails, and a longitudinal ½″×½″ groove is formed centrally of the cut face of each rail. Three ½″ thick OSB web pieces of predetermined length and width are cut and glued and stapled into the rail grooves. This produces a finished board dimensionally equivalent to a standard 2″×8″ board that has gaps between the rails that enable conventional plumbing pipes, electrical wiring, HVAC ducting, and insulation to pass laterally through the board when used as a stud.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates to wood lumber and, more particularly, to standard sized lumber used for building structures that is modified to create larger sizes from smaller sizes. These lumber boards are commonly used for studs, joists and sills. All lumber sizes referenced herein are standard nominal dimensions, such as 2″×4″, although the standard actual dimensions are smaller, such as 1¾″×3½″.

2. Background Art

The 2″×4″ (nominal dimensions; actual dimensions=1½″×3½″) board of various lengths are the most common wood boards used in home and apartment building, especially for wall studs. Also commonly used are the 2″×6″ (nominal dimensions; actual dimensions=1½″×5½″), and 2″×8″ (nominal dimensions; actual dimensions=1½″×7¼″) boards. Less often used are 2″×10″ (nominal dimensions; actual dimensions=1½″×9¼″) boards, or 2″×12″ (nominal dimensions; actual dimensions=1½″×11¼″) boards.

In higher end homes, the single 2″×4″ wall is replaced by a 2″×6″ wall. In some cases, the single 2′×4′ wall is being replaced by staggered double 2′×4′ outside walls in building houses and apartments to provide space for more insulation for temperature maintenance and for sound deadening, particularly in higher priced housing units. When the double 2″×4″ double wall is used, the studs are staggered, forming so-called “wishbone” walls. Of course, the use of the double wall doubles the labor required for installation.

A standard 4-unit apartment building uses about 1000 studs. In the Midwest the cost (varies from time to time) of such a standard stud is $2.44; and the stud cost for a building would be $2440. A double wall costs $4880; in addition, the labor time also doubles, further increasing costs. By using 2″×6″ studs ($4.70 each), the lumber cost raises to $4700, although the labor cost is reduced back to the single wall cost. Using 2″×8″ studs ($7.50 each) costs $7500, at single wall labor cost. If the cost of studs could be reduced, there would be a substantial material savings and, in the case of a double wall, labor savings as well.

There is a need for studs that can provide the desirable double wall construction, but at a less than current cost in materials and labor.

The standard solid length wood studs used in building housing units must often be drilled or otherwise cut away to provide space for running plumbing pipes and electrical wiring laterally, although wiring can be snaked through the staggered double walls. Traversing HVAC ductwork is more difficult to accommodate, most often necessitating the use of soffets, since it is difficult to accurately cut away sufficient portions of the studs to accommodate their passage without weakening the studs. This is also true of the use of 2″×8″ studs to a lesser extent. All of these accommodations increase labor costs.

In addition, 2″×8″ studs are used in an outside wall, there is a 1½″ wide solid wood rib from inside to outside that cannot be insulated, thus having discontinuous lateral insulation. Wood has a much lower R-value than insulation and much poorer sound deadening capabilities. This renders the 2″×8″ wall somewhat inferior to the double 2″×4″ wall, which has continuous lateral insulation.

It is also desirable to provide a wood stud that enables transverse wiring, plumbing piping and HVAC ductwork to be more easily and economically accommodated, and which permits continuous lateral wall insulation.

There have been numerous attempts to replace standard lumber with composite wood I-beams, box beams, metal beams, and others. Among these is U.S. Pat. No. 6,460,310—Ford et al, which discloses a composite I-beam that has a continuous OSB or plywood web connecting a pair of spaced grooved rails formed of laminated veneer lumber. This is used as a floor joist. U.S. Pat. No. 2,230,628—Sahlberg features an I-beam formed of a plywood web connecting plywood rails reinforced by wood blocks U.S. Pat. No. 5,609,006—Boyer discloses an I-shaped stud formed of metal channels interconnected by spaced web pieces made of polyethylene, providing gaps to allow passage of wiring, etc. However, all of these designs are expensive and complicated.

SUMMARY OF THE INVENTION

Thus it is an object of this invention to provide wood lumber studs that can provide the benefits of both the double 2″×4″ wall and the 2″×8″ wall, but at a less cost in materials and labor.

It is another object of this invention to provide studs that can provide the desirable double wall construction, but at a less than current cost in materials and labor.

It is a further object of this invention to provide a wood stud that enables transverse wiring, plumbing piping and HVAC ductwork to be more easily and economically accommodated, and which permits continuous lateral wall insulation.

In one aspect, his invention generally features providing an engineered board by bifurcating a 2″×4″ board lengthwise into two equal rails. The rail cut faces are centrally grooved (dadoed) lengthwise and two spaced OSB or other composite boards are inserted at the ends and an optional third board is placed in the middle of the grooves, where they are glued and nailed to produce a lightweight 2×8 replacement. When used as studs, the inherent large gaps accommodate HVAC ducting, plumbing pipes, electrical lines, and insulation.

In another aspect, this invention features a method of producing an engineered board of standard width from a beginning standard board of narrower width.

Features of the engineered boards according to this invention, and advantages of using compared to standard lumber boards, are

-   1. Lighter weight -   2. Lower material costs -   3. Corrects warpage -   4. Provides gaps for wiring, plumbing, ducting and insulation -   5. Enables superior heat and sound insulation -   6. Reduces labor costs. -   7. When used as studs and sill boards, enables use of blown in foam     insulation to secure side sheeting directly to floors.

These and other objects and features of this invention will become more readily apparent upon reference to the following detailed description of a preferred embodiment, as illustrated in the accompanying drawings, in which:

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial plan view of a standard 2″×4″ wood board;

FIG. 2 is a a partial view of the board of FIG. 1, but shown after being longitudinally bifurcated into two rails and spread;

FIG. 3 is a detail view of the center of the bifurcated board with web board between the rails before assembly;

FIG. 4 is a detail view of one end of the bifurcated board with web board between the rails before assembly;

FIG. 5 is an enlarged detail transverse sectional view showing the web piece inserted into a rail groove after gluing and stapling'

FIG. 6 is a transverse sectional view of the finished assembled board after insertion, gluing and stapling of the web pieces; and

FIG. 7 is a plan view of the finished engineered board, illustrating the accommodation of plumbing piping in the spaces between the web pieces.

DETAILED DESCRIPTION OF THE INVENTION

This invention provides an engineered 2″×8″ equivalent board that is formed from a standard wood 2″×4″ board. As shown in FIGS. 1 and 2, a 2″×4″ board 10 is cut into two equal lengths (bifurcated) longitudinally to form opposed rails 12 and 14. Longitudinal ½″×½″ grooves 16, 18 are formed centrally of the cut face rails 12, 14.

As shown in FIGS. 3 and 4, three nominally ½″ thick OSB web pieces 20, 22, 24 (see FIG. 7) of predetermined length and width are cut. In his instance, the length is preferably 12″ or 16″, while the width is approximately 4¾″—sufficient to make an assembled finished engineered board having the width of a standard 2″×8″ (7¼″ actual).

Rails 12, 14 are spaced apart with grooves 16, 18 facing each other (FIG. 3). A common wood glue (not shown) is inserted into grooves 16, 18 and web pieces 20, 22, 24 are fitted adjacent the ends and in the middle of the rails (see FIG. 7). This assembly is clamped together by conventional clamps (not shown) in a fixture (not shown) and staples 26 are driven through rails 12, 14 and the corners of each web piece 20, 22, 24 (FIGS. 5 and 6). The assembly can now be immediately unclamped, since the staples hold the pieces clamped together until the glue has set. This produces a finished I-shaped board 28 dimensionally equivalent to a standard 2″×8″ board.

The finished board 28 has gaps 30, 32 between rails 12, 14 that enable conventional plumbing pipes (34, 36, 38, and electrical wiring, HVAC ducting, and insulation (not shown) to pass laterally through the board when used as a stud.

While only a preferred embodiment has been described and shown, obvious modifications are contemplated within the scope of this invention as defined by the following claims. 

1. An engineered wall stud comprising a standard wood 2″×4″ board bifurcated longitudinally to form opposed rails, a longitudinal groove formed centrally of one face of each rail, said grooves facing each other when the rails are spaced apart, a pair of spaced web pieces fitted and secured in the grooves adjacent the ends thereof to secure the rails together and form a finished stud of greater width than a 2″×4″ board, whereby said web pieces create a gap between the rails that enables conventional plumbing pipes, electrical wiring and insulation to pass laterally through the stud when placed in a wall.
 2. The engineered wall stud of claim 1, including at least one additional web piece fitted and secured in the grooves between said pair of spaced web pieces.
 3. The engineered stud of claim 1, wherein the greater width of the finished stud equals the width of a standard board, selected from the group composed of 2″×6″, 2″×8″, 2″×10″, and 2″×12″ boards.
 4. The engineered stud of claim 3, wherein each groove is ½″ deep, and each web piece is glued to the rails in the grooves.
 5. The engineered stud of claim 4, wherein the standard board is a 2″×8″ board.
 6. The engineered stud of claim 1, wherein the web pieces are made of a wood-based composite material.
 6. The engineered stud of claim 6, wherein the composite material is OSB.
 8. The engineered stud of claim 1, wherein the grooves are approximately ½″×½″ and formed in the cut faces of the rails, the web pieces are ½″ thick OSB boards, and the greater width of the finished stud equals the width of a 2″×8″ board.
 9. A method of creating an engineered structural board from a narrower standard-size wood board comprising the steps of a. bifurcating a beginning standard size board to form two opposed rails, b. forming a longitudinal groove of predetermined depth and width centrally of the cut face of each rail, said grooves facing each other when the rails are spaced apart, c. forming a pair of web pieces from OSB to a predetermined length and width, said web pieces having a thickness equal to the width of the grooves, d. inserting glue into the grooves adjacent the ends of each board, e. assembling each of the web pieces into he groove of one of the rails adjacent the rail ends to engage the glue, f. assembling the other rail onto the web pieces, with the web boards engaging the glue in the groove, g. laying the assembly flat with the web pieces located horizontally and clamping the assembly, h. mechanically fastening each corner of each web piece to the rails, and i. removing the clamps, thereby producing a finished board having a width greater than the beginning board.
 10. The method of claim 9, including the steps of producing a third web piece having a width and thickness equal to that of said pair of web pieces of step c., and inserting said third web piece, between and along with said pair of web pieces, as in steps e. and f., centrally of said grooves.
 11. The method of claim 9, wherein the beginning board is a 2″×4″ board, and the finished board is a 2″×8″ board.
 12. An engineered building structural board comprising a beginning standard wood board, selected from the group composed of 2″×4″, 2″×6″, 2″×8″ board sizes, bifurcated longitudinally to form opposed rails, a longitudinal groove formed centrally of one face of each rail, said grooves facing each other when the rails are spaced apart, a pair of spaced web pieces fitted and secured in the grooves adjacent the ends thereof to secure the rails together and form a finished board of greater width than the beginning board, whereby said web pieces create a gap between the rails.
 13. The engineered building structural board of claim 11, wherein the finished board is a standard size selected from the group consisting of 2″×6″, 2″×8″, 2″×10″ and 2″×12″ boards. 